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Electronic structure of correlated topological insulator candidate YbB6 studied by photoemission and quantum oscillation

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Chinese Physics B 2020年第1期29卷 70-75页

作者： T Zhang G Li s C sun N Qin L Kang s H Yao H m Weng s K mo L Li Z K Liu L X Yang Y L Chen state Key Laboratory of Low Dimensional Quantum Physics Department of PhysicsTsinghua UniversityBeijing 100084China Department of Physics University of MichiganAnn ArborMI 48109USA Beijing National Laboratory for Condensed matter Physics and Institute of Physics Chinese Academy of SciencesBeijing 100190China National Laboratory of solid state microstructures&Department of materials science and Engineering Nanjing UniversityNanjing 210093China Collaborative Innovation Center of Quantum matter BeijingChina songshan Lake materials Laboratory Dongguan 523808China CAs Center for Excellence in Topological Quantum Computation Beijing 100190China Physical science Laboratory Huairou National Comprehensive Science CenterBeijing 101400China Advanced Light source Lawrence Berkeley National LaboratoryBerkeleyCA 94720USA school of Physical science and Technology ShanghaiTech University and CAS-Shanghai Science Research CenterShanghai 201210China shanghaiTech Laboratory for Topological Physics Shanghai 200031China Frontier science Center for Quantum Information Beijing 100084China Department of Physics Clarendon LaboratoryUniversity of Oxford Parks RoadOxford OX13PUUK

Angle-resolved photoemission spectroscopy(ARPEs)and torque magnetometry(Tm)measurements have been carried out to study the electronic structures of a correlated topological insulator(TI)candidate Yb *** observed clear surface states on the[001]surface centered at theГ^- and М^- points of the surface Brillouin ***,the fermiology revealed by the quantum oscillation of Tm measurements agrees excellently with ARPEs ***,the band structures we observed suggest that the band inversion in Yb B6 happens between the Yb5 dand B2bands,instead of the Yb5dand Yb4fbands as suggested by previous theoretical investigation,which will help settle the heavy debate regarding the topological nature of samarium/ytterbium hexaborides.

关键词： topological insulator electronic structure surface states

Cadmium sulfide thin films growth by chemical bath deposition

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Journal of semiconductors 2018年第3期39卷 50-56页

作者： s.Hariech m.s.Aida J.Bougdira m.Belmahi G.medjahdi D.Genève N.Attaf H.Rinnert Thin films and Interfaces Laboratory Faculty of Sciences Mentouri University Department of physics Faculty of science King Abdulaziz University Jean Lamour Institute University of Lorraine

Cadmium sulfide（Cd s） thin films have been prepared by a simple technique such as chemical bath deposition（CBD）. A set of samples Cd s were deposited on glass substrates by varying the bath temperature from 55 to 75 °C at fixed deposition time（25 min） in order to investigate the effect of deposition temperature on Cd s films physical properties. The determination of growth activation energy suggests that at low temperature Cd s film growth is governed by the release of Cd^（2＋） ions in the solution. The structural characterization indicated that the Cd s films structure is cubic or hexagonal with preferential orientation along the direction（111） or（002）, respectively. The optical characterization indicated that the films have a fairly high transparency, which varies between55% and 80% in the visible range of the optical spectrum, the refractive index varies from 1.85 to 2.5 and the optical gap value of which can reach 2.2 e V. It can be suggested that these properties make these films perfectly suitable for their use as window film in thin films based solar cells.

关键词： thin films chemical bath cadmium sulfide solar cell

Effects of varying alx moles on structure and luminescence properties of Znal_(x)O_(1.5x+1):0.1 mol%Tb^(3+)nanophosphors prepared using citrate sol-gel method

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Journal of Rare Earths 2023年第3期41卷 358-364,I0002页

作者： V.m.maphiri L.T.melato m.R.mhlongo T.T.Hlatshwayo T.E.motaung L.F.Koao s.V.motloung Department of Physics Sefako Makgatho Health Science UniversityP.O.Box 94Medunsa0204South Africa Department of mathematics Non Destructive Testing and PhysicsVaal University of TechnologyAndries Potgieter BlvdVanderbijlpark1900South Africa Department of Physics University of PretoriaPretoria0002South Africa Department of Chemistry School of Science in the College of Science Engineering and TechnologyUniversity of South AfricaPreller StreetMuckleneuk RidgeCity of TshwaneP.O Box 392UNISA 0003South Africa Department of Chemistry Sefako Makgatho Health Science UniversityP.O.Box 94Medunsa0204South Africa Department of Physics University of the Free State(Qwaqwa Campus)Private Bag X13Phuthaditjhaba 9866South Africa Department of Chemical and Physical sciences Walter Sisulu UniversityMthathaSouth Africa

Un-doped and Znal_(x)O_(1.5x+1):0.1 mol%Tb^(3+)(ZAOT)nano-powders were synthesized via citrate sol-gel *** AIx moles were varied in the range of 0.25≤x≤*** X-ray powder diffraction(XRD)data reveal that for xed samples crystal structure consists of mixed phases of the cubic Znal_(2)O_(4) and hexagonal ZnO phases,while for x>1.5 the structure consists of single phase of cubic Znal_(2)O_(4).The Raman and Fourier-trans form infrared(FTIR)vibrational spectroscopy show the presence of vibrations emanating Znal_(2)O_(4) *** electron microscopy(sEm)and transmission electron microscopy(TEm)show the presence of irregular sphere at x>2.0 attributed to Znal_(2)O_(4).The photoluminescence(PL)spectroscopy reveals emissions from both the host and Tb^(3+)*** from Tb^(3+)are observed at 382,414,439,458 nm and 489,545,585,621 nm,which were attributed to the^(5)D_(3)→^(7)F_(6,5,4,2) and ^(5^)D_(4)→^(7)F_(6,5,4,3),*** results confirm that the Tb^(3+)occupation site depends on the alx *** International Commission on Illumination(CIE)colour chromaticity shows that the emission colour can be tuned from blue to green by varying the AIx moles.

关键词： Citrate sol-gel Znal_(2)O_(4)/ZnO Tb^(3+)-doped al_(x)moles Photoluminescence Rare earths

shallow Geothermal Energy Resources for Future Utilization in Jordan

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Open Journal of Geology 2019年第11期9卷 783-794页

作者： sanaa al-Zyoud Department of Applied Earth and Environmental sciences Institute of Earth and Environmental Sciences Al al-Bayt University Al Mafraq Jordan

Geothermal energy is considered as one of the new-green-free renewable energy resources that Jordan is blessed with. Geothermal energy installation in Jordan will have a positive impact on the economy, it will reduce the national energy bill. shallow geothermal systems are likely to be promising for future utilization in the country. Therefore, further evaluations of geothermal energy resources are highly recommended. Distributed efforts have been done to evaluate the potential of geothermal resources utilization in Jordan. A comprehensive geothermal resources assessment has not yet been conducted in the country. The present work evaluates the potential of four geothermal fields in Jordan. Geothermal gradient map shows that Jordan has two high geothermal gradient fields with higher than 4.5°C/100m and other two moderate geothermal gradient fields with a range of 3.5 - 4.5°C/100m. It has been found that the water temperature in some fields reaches about 68.5°C. Five possible heat source hypotheses were discussed. Geothermal potential in Jordan is expected to evolve as a result of Ns trending Dead sea Rift activities. With the presence of faults parallel with geothermal gradient anomalies in each evaluated field, this hypothesis becomes the most effective to explain the heat source. It is of utmost importance to consider the geothermal energy potential for future utilization in Jordan. An integrated geothermal potential map will be very helpful for energy policies and future strategies planning in the country.

关键词： Geothermal Field Geothermal Gradients Tectonic Activities Heat source Jordan

Impedance spectroscopy and DFT/TD-DFT studies of diyttrium trioxide for optoelectronic fields

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Journal of Rare Earths 2023年第4期41卷 605-612页

作者： ali A.alkathiri A.A.Atta moamen s.Refat sonam shakya A.m.Hassanien saud A.algarni Emad m.A.Ahmed sultan E.alomariy m.ham.ed alsawat Norah algethami Department of Physics College of ScienceTaif UniversityP.O.Box 11099Taif21944Saudi Arabia Department of Chemistry College of ScienceTaif UniversityP.O.Box 11099Taif21944Saudi Arabia Department of Chemistry Aligarh Muslim UniversityAligarh202002India Department of Physics Faculty of Science and Humanity Studies at Al-QuwayiyahShaqra UniversityAl-Quwayiyah11971Saudi Arabia

Yttrium(Ⅲ)oxide or so-called diyttrium trioxide(Y_2O_3)is an excellent candidate ceramic material for optoelectronic ***,electrical conductivity,and dielectric relaxation properties of bulk yttrium(Ⅲ)oxide were studied.X-ray diffraction(XRD)results indicate that the yttrium(Ⅲ)oxide compound has a crystalline cubic *** transform infrared(FTIR)technique was used to ascertain the chemical structure of the yttrium(Ⅲ)oxide *** spectroscopy was used to analyze frequency-dependent electrical properties as a function of temperature in the range of 303-423 K and frequency range of 0.1 Hz-2 *** spectroscopy parameters such as dielectric constant,dielectric loss,loss factor,electric modulus,and complex impedance of the yttrium(Ⅲ)oxide compound were *** Nyquist plot describes the complex impedance of the yttrium(Ⅲ)oxide for different *** universal Jonscher's power law was used for the analysis of the complex electrical conductivity of the yttrium(Ⅲ)oxide *** is found that the real(σ')and imaginary(σ")parts of the complex conductivity increase with increasing *** exponent frequency(s)equals unity,which confirms that the predominant conduction mechanism is a nearly constant loss(NCL)***/TD-DFT studies using B3LYP/LanL2DZ level of theory were used to provide comparable theoretical data and electronic energy gap of HOmO→LUmO.

关键词： Yttrium(Ⅲ)oxidel Impedance spectroscopy DFT/TD-DFT Rare earths

Evaluation of leptin,interleukin-1 beta and tumor necrosis factor alpha in serum of malaria patients as prognostic markers of treatment outcome

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Asian Pacific Journal of Tropical Biomedicine 2014年第6期4卷 441-445页

作者： mariam Abdulrhman al-Fadhli mohammad Ahmed saraya Jafar Abdulrida Qasem Department of medicine.Infectious Disease Hospital Ministry of Health Department of Tropical medicine.Faculty of medicine.Zagazig University Department of Applied medical sciences College of Health SciencesPublic authority for Applied Education and Training

Objective:To analyze scrum leptin levels in patients with malaria falciparum and compare them with healthy controls and correlate with development and outcome of malaria ***:sixty cases of malaria falciparum were included in this study as *** healthy individuals of comparable age,racial and body mass index were taken as *** patients were diagnosed by clinical picture and the presence of malaria parasites in blood *** of liver function test,kidney function test,complete blood count,fasting blood sugar,fasting serum insulin,pro-inflammatory cytokine tumor necrosis factor alpha(TNFα)and interleukin 1(IL1),estimation of morning serum leptin and calculation of body mass index(kg/m^2)were done in both groups on the day of admission,on discharge and 7 d after ***:At admission,leptin levels were significantly higher in patients group than in control while lasting serum insulin levels were not significantly different between the two *** were significant increases as regard to TNFαand IL1 in malaria *** differences were observed between the control and the patient group for leptin,TNFαand IL1 at the time of admission and *** discharge for 7 d.a significant decline in scrum leptin levels,TNFαand IL1 in the patients group was observed as compared with time of admission and time of discharge,a positive correlation between serum leptin levels and TNFαand ***:Leptin hormone level might play an important role in development and outcome of malaria infection.

关键词： malaria.Leptin IL-1 Tumor necrosis factor alpha(TNFα) Kuwait

Growth Profile of Gilthead Bream Reared in mega Flow Re-circulating Aquaculture system

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Journal of Agricultural science and Technology(A) 2014年第4期4卷 307-314页

作者： mohammad al-Zibdah Faculty of marine science University of Jordan/Aqaba Branch Aqaba 77110 Jordan

This study was designed to compare the effect of two exchange rates （ERs; 0.5 m^3 feed/kg and 1.5 m^3 feed/kg） in re-circulating aquaculture systems （RAs） on water quality and fish growth profiles on fish stocks （200 indiv/m^3 of 251.4 g e 20.67 g） of gilthead bream, sparus aurata. Water quality, fish growth, specific growth rate （sGR） and feed conversion ratio under the two ERs were examined for a period of six months. Inorganic nutrient in RAs, temperature, dissolved oxygen and pH were measured daily. Feeding regime effect was also determined on the fish quality and organoleptic characteristics and thus opts to energy optimization of the system. The fish reared under the 1.5 m^3 feed/kg ER demonstrate enhanced growth, the daily sGR and the conversion ratio. sensory test analysis revealed differences in the organoleptic characteristics between the two experimental fish stocks with considerably high acceptance scores for fish reared at high ER. Nutrient concentrations： ammonia, nitrate, nitrite and phosphate were lower in RAs of the highest ER when compared to those reared under the 0.5 m3/kg feed. Results suggest an ER of 1.5 m^3 feed/kg improved both fish quality and growth profile of the gilthead bream.

关键词： RAs gilthead sea bream ER growth conversion rate.

monthly and seasonal Investigation of Wind Characteristics and Assessment of Wind Energy Potential in al-mokha, Yemen

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Energy and Power Engineering 2012年第3期4卷 125-131页

作者： mahyoub H. al-Buhairi Ahmed al-Haydari Physics Department Faculty of Applied Science Taiz University Taiz Yemen

The negative effects of fossil fuels have forced many countries to explore clean energy sources that are both environmenttally more suitable and renewable. In this study, wind characteristics and assessment of wind energy potential, were analyzed using the wind speed data measured during the period 1995-2001 at 10 m height of al-mokha, located in the west of Taiz, in the southwest of Yemen, subjected to 2-parameter Weibull analysis. Based on these data, it was found that the monthly mean wind speed ranged from 3.50 m/s in June to 7.94 m/s in November, the monthly values of Weibull shape parameter (k), ranged from 3.09 to 6.26, while the value of scale parameter (c) ranged from 3.91 to 8.63 m/s and the monthly wind power density ranged from 33.08 to 352.43 W/m2. The seasonal mean wind speed data ranged from 3.61 to 7.56 m/s, while the wind power density was ranged from 36.62 to 328.59 W/ m2 for summer and winter, respectively.

关键词： al-mokha Yemen Weibull Distribution Wind Energy

The Effect of （Ag） Addition on some mechanical Properties of （al-si） alloy

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Journal of Physical science and Application 2016年第1期6卷 131-136页

作者： alhak A. Hassan Abdulazeez O. mousa Jassim m. al-murshdy Department of Physics College of Science University of Babylon Babylon Iraq Department of metallurgy College of Materials Engineering University of Babylon Babylon lraq

aluminum casting alloys with silicon as the major alloying elements are the most important commercial casting alloys because of their superior casting characteristics and as it is well known that （AI-si） alloys, which are widely applied in the aerospace and automotive industries. This research aims to study the effect of Ag element addition on hypo and hypereutectic （AI-si） alloy. In this research microhardness and corrosion resistance was calculated by Vickers device and electrochemical method respectively to base alloys before and after the addition of Ag, and also the effect of artificial ageing time was studied at temperature （160 ℃） after the addition of Ag. The results shown that the addition of Ag led to increase microhardness, decrease corrosion resistance and the best time of artificial ageing was 10 hrs.

关键词： (al-si) alloy alloying elements corrosion resistance artificial ageing microhardness.